Electric circuit interrupter



NOV. 23, 1943. B, R, HERMANN 2,335,062

ELECTRIC CIRCUIT INTERRUPTER Filed Dec. 24, 1941 Inventor: Benjamin R. Hermann,

52 37 2 ,5. Z5 HIS Attorney Patented Nov.- 23, 1943 Benjamin B.. Hermann,

signor to General Electric Company,

tion of New York Lanesborough, Mass., as-

a corpora- Application December 24, 1941, Serial No. 424,317

(Cl. 20G-114) 9 Claims.

My invention relates to electric circuit interrupters and more particularly to a fuse cutout type of circuit interrupter.

It is an object of my invention to provide a new and improved fuse cutout type o! circuit interrupter.

It is another object of my invention to provide a new and improved terminal which may be readily used with an electric circuit interrupter such as a fuse cutout.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a side elevation partly in section of an electric circuit interrupter of the fuse cutout type embodying my invention, Fig. 2 is a view taken on line 2-2 of Fig. i, Fig. 3 is a view taken' on line 3-3 of Fig. 1, Fig. 4 is a view taken on line 4-4 of Fig. 1, and Fig. 5 is an exploded view showing a portion of the apparatus of Fig. l.

Referring now to the drawing, I indicates a housing or casing of porcelain or similar insulating material having an integrally formed creepage barrier I0' which separates two stationary terminal or contact assemblies generally indicated at II and I2, respectively, mounted within housing I0. Contact assembly II, best shown in Figs. 1 and 3, consists of three metal elements I3, I4 and I5, all riveted together by means of rivet elements i6. The element I3 serves as a support or spring latch, the ends I3 of which engage abutments formed by recesses or notches I1 in the walls of housing or casing I0. The upper part of housing I0 is also provided on each side with a pair of integrally formed spaced projections I8 (see Fig. 2). These projections serve as barriers to prevent the contact assembly II from being displaced from its latched position between the projections I8 with the ends'IS of the support I3 being engaged with the abutments formed by the recesses I1 in housing I0. The member I4 of contact assembly II is a spring contact or terminal clip for engaging with a cylindrical contact of a fuse device, ior example, to be described hereinafter.

The-support I3 is provided with lanced out portions I3" which act as backing members for limiting the movement of spring clip I4. The member I5 includes a looped or cylindrical leadreceiving portion or passageway i5. A plurality of screws I8 are provided in the cylindrical leadreceiving portion I5 for clamping a conductor or lead inserted in the lead-receiving portion or passageway I5'. The lead-receiving portion I5 of contact assembly II is mounted adjacent a lead entrance opening 20 in the upper part of housing I0 through which external connections with the contact assembly II may be made.

The contact assembly I2 is substantially identical with the contact assembly li described above and is mounted adjacent lead entrance opening 2l between projections 22 in the lower part of housing or casing Il). Contact assembly I2 includes members I3 and I5 identical with the corresponding members of contact assembly II and the ends I3' of member I3 are adapted to engage abutments formed by recesses or notches 23 substantially identical with the notches I1 described above. A contact clip 2| is provided in contact assembly I2 (Fig. 4) which differs from the corresponding member Il of contact assembly II only in that it is shaped to engage a rectangular-shaped contact member instead of a cylindrically shaped member. The other corresponding portions of contact assembly I2 are designated by the same reference numerals as these portions of contact assembly II.

The contact or terminal assemblies II described thus far and the method of supporting. them in housing Iu are not my invention but are disclosed and claimed in United States Letters Patent 2,011,391, granted August 13, 1935, upon an application of R. S. Bennett, and assigned to the same assignee as the present application.

To the back of the housing I0, there is secured a mounting bar 25 for attachment of the cutout to a suitable supporting structure, notl shown. This mounting bar 25 is preferably cemented as at 26 into an external recess 21 in housing I0.

In order to provide a closure for housing III, I provide. a cover or door 28 preferably made of a molded insulating compound or the like which includes an integral handle or eye 29 which may be either grasped manually or engaged by a suitable form of switch stick to open and close the cover 28 with respect to housing I0. Door 28 is pivotally mounted to the lower front portion oi housing IIl by means of an insulated hinge pin 30 which passes through an opening 3I in the lower portion of door 28 and extends into openings 32 (see Fig. 2) on the lower iront portion of housing I0. The pin 30 of insulating material is prevented from falling out by means of a suitable member, such as screw 33 (Fig. l) which and i2 2 is threaded into pin 30 through an opening or hole 34 in the inside surface of door 28 intersecting the threaded opening in the hinge pin. With the arrangement ,Just described, a nonmetallic hinge is provided thereby eliminating all exposed metal parts from the cutout door. 'Ihe cover 28 is also provided with a plurality of barriers 28' integrally formed with the inner surface of the door which cooperate with creepage barrier I' of housing I9 to lessen the possibility of fiashover between contact assemblies and I2 by virtue of conducting gases passing therebetween.

The cover or door 28-is adapted to support a cylindrical fuse tube 35, which may be of conventional construction. I have illustrated this fuse tube 35 as having a cylindrical upper terminal 38 and a lower terminal 31 to be described in greater detail hereinafter. The terminals 35 and 31 are adapted to engage with the corresponding terminal or contact clips I4 and 24 of contact assemblies and I2, respectively. By using a cylindrical terminal terminal 31 good contact alignment is always insured. Mounted within fuse tube 35 is the conventional fuse link, preferably of the buttonhead type, which is held in position in conducting engagement with the upper terminal 38 by means of a cap 39 screwed to a threaded portion of terminal member 35 fastened to the upper end of fuse tube 35. As will be understood by those skilled in the art, the fuse link mounted within fuse tube 35 includes a fusible element with a flexible conductor 49 connected to the lower terminal of the fusible element. In the drawing, only the flexible conductor 40 of the fuse link is visible except for the small crosssection shown in Fig. 3. As will be understood, the fuse device including fuse tube 35 and the fuse link, 'only the flexible conductor 48 of which is visible in Figpl, operates on the expulsion principle to interrupt the electric circuit therethrough.

The upper end of fuse tube 35 is secured to the cover 28 by means of a metal support 4| having an opening 42 therethrough through which the cap 39 may be inserted. Cap 39 is provided with an enlarged knurled portion 43 which will not pass through the opening 42 in support 4|, thereby preventing longitudinal motion of the fuse tube 35 as a result of a recoil upon rupture of a fusible element. Furthermore, this enlargement also serves to position the fuse tube properly relative to door 28. Member 4| is fastened to the upper portion of door 28 by any suitable means and may include a spring member 44 to firmly connect electrically the upper portion of fuse tube 35 to member' 4|. The lower portion of fuse tube 35 is held to door 28 by means of a spring clip 45 fastened to the inner side of door 28 and may also include a spring member 48 similar in position and function to the spring member 44 associated with member 4|.

The lower terminal 31 and the means of fastening it to fuse tube 35 are best shown in the exploded view of Fig. 5. Preferably, terminal 31 comprises a 4formed stamping somewhat U- shaped with right angles at thebase of the U to furnish a rectangular contactl for engaging terminal clip 24. The lower portion of fuse tube 35 is provided with a recess 41 therein for accommodating a key which is illustrated as a bolt 48 Yhaving a head 49 which is shaped so that it will not turn when inserted in the recess 41 in fuse 38 and a square tube 35. .As illustrated, head 48 is rectangular in shape. Bolt 48 is adapted to be inserted through an opening 50 in terminal 31, whereupon terminal 31 is arranged sc as partially to encircle fuse tube 35 with the key comprising the head 49 of bolt 48 inserted in recess 41 of fuse tube 35, whereby longitudinally to position terminal 31 on fuse tube 35. Theterminal 31 is providedon either side thereof with a plurality of arms 5| which are clamped or bent around fuse tube 35 after the terminal and key are in position so as to prevent the key comprising head 49'of bolt 48 .from being withdrawn from recess 41, thereby suitably fastening terminal 31 to fuse Y tube 35 in a simple and yet a very eifective manner. A knurled nut 52. may be provided for bolt 48, whereby flexible cable 40 may be electrically connected to terminal 31 as shown in Figs. 1 and 2. k'Ihe method of fastening the lower terminal 31`""ei`ables it to have a slight floating action on fuse tube 35 to insure good contact alignment between terminal 31 and terminal or contact clip 24.

In order to prevent the insertion of fuse tube 35 into supporting clip 45 in any but the correct position, terminal 31 may be provided with upwardly projecting lugs 53 and 54, incorrect positioning being rejected by spring supporting clip 45 as will be obvious from Figs. 1 and 2 of the drawing.

When the fuse tube 35 is mounted on door 28 in the manner indicated in Figs. 1 and 2, the door maybe held in the closed and latched position by means of contact clip |4 of upper contact assembly While I have shown and described what I at present consider the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from my invention and I, therefor aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my in- What I claim as new and desire to secure by Letters Patent of the United States is: 1. In an electric device, an insulating member, a terminal for said member arranged to be mounted exteriorly of said member and adapted for partially encircling said member, a recess in the exterior surface of said member, a key cooperating with said recess and said terminal longitudinally to position said terminal on said member, and a plurality of arms associated with said terminal adapted to be clamped around said member for holding said terminal against longitudinal movement on said member by maintaining said key in said recess.

2. In an electric device, a fuse link, a fuse tube for said fuse link, a terminal for said fuse tube arranged to be mounted exteriorly of said fuse tube and adapted for .partially encircling said fuse tube, a recess in the exterior surface of said fuse tube, a key cooperating with said recess and said terminal longitudinally to position said terminal on said fuse tube, and a plurality of arms associated with said terminal adapted to be clamped around said fuse tube for holding said terminal against longitudinal movement along said fuse tube by maintaining said key in said recess.

3. In an electric device, a fuse link including a fusible element, a fuse tube for said fuse link, a terminal for said fuse link arranged to be mounted exteriorly of said fuse tube and adapted for partially encircling said fuse tube, said terminal having an opening therein, a recess in the exterior surface of said fuse tube, a bolt arranged for insertion in said opening in said terminal and having a rectangular portion for cooperating with said recess as a key longitudinally to position said terminal on said fuse tube, and a plurality of arms associated with said terminal for holding said terminal on said fuse tube by maintaining the rectangular-shaped head of said bolt insaid recess.

4. In an electric device, a fuse link including a fusible element, a fuse tube for said fuse link, a terminal for said fuse link including an opening therein arranged to be mounted exteriorly of said fuse tube and adapted for partially encircling said fuse tu a. recess in the exterior surface of said fuse tube, a bolt arranged for insertion in said opening in said terminal and having a portion for cooperating with said recess as a. key longitudinally to position said terminal on said fuse tube, a plurality of arms associated with said terminal for holding said terminal on said fuse tube by maintaining the portion of said bolt acting as a key in said recess, and means cooperating with said bolt for fastening one end of said fuse link to said terminal.

5. In an electric device, a fuse link including a fusible element, a fuse tube for said fuse link, a terminal for said fuse link including an opening therein arranged to be mounted exteriorly of said Iuse tube and adapted for partially encircling said fuse tube, a recess in the exterior surface of said fuse tube, a bolt arranged for insertion in said opening in said terminal and having a rectanglarly-shaped portion for cooperating with said recess as a key longitudinally to position said terminal on said fuse tube, a plurality of arms associated with said terminal for holding said terminal on said fuse tube by maintaining said rectangular-shaped portion of said bolt in said recess, and a knurled nut for said bolt for fastening one end of said fuse link to said terminal.

6. In an electric device, an insulating member, a terminal for said member comprising a formed stamping of metal arranged to be mounted exteriorly of said member and adapted for partially encircling said member, a recess in the exterior surface of said member, a key cooperating with said recess and said terminal longirality of projecting tudinally to position said terminal on said member, and a plurality of arms associated with said terminal for holding said terminalon said member by maintaining said key in said recess.

'7. A cutout having a housing, a door i'or closing an open side of said housing, a pair of contact assemblies located in said housing and each provided with means for receiving a terminal of a fuse device, a fuse tube including a pair of terminals, a fuse link including a fusible element interconnecting said terminals, means for supporting said fuse tube on said door, and means associated with one of said terminals cooperating with said last-mentioned means for preventing incorrect positioning of said fuse tube on said door.

8. A cutout having a housing, a door for closing an open side of said housing, a pair of contact assemblies located in said housing and each provided with means for receiving a terminal of a fuse device, a fuse tube including a pair of terminals, a fuse link including a fusible element interconnecting said terminals. a spring clip for supporting said fuse tube on said door, and a plulugs associated with one of said terminals to cooperate with said spring clip and prevent incorrect positioning of said fuse tube on said door.

9. A cutout having a. housing, a door for closing an open side of said housing, a pair of spaced contact assemblies located in said housing and each provided with means for receiving a terminal of a fuse device, a fuse tube including a pair of spaced terminals, a fuse link including a fusible element interconnecting said terminals, a cap for the upper end of said fuse tube, means for supporting the upper end of said fuse tube on said door comprising a support having an opening therethrough to receive said cap, means for limiting the longitudinal motion of said fuse tube as a result of recoil upon rupture of said fusible element comprising an enlarged portion on said cap incapable of passing through the opening in said support, means for supporting the lower end of said fuse tube on said door comprising a spring clip, and a plurality of projecting lugs associated with one of said terminals cooperating with said spring clip to prevent incorrect positioning of said fuse tube on said door.

BENJAMIN R. HERMANN. 

